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"Pirate" electrolytic caps - identifying?

Discussion in 'Electronic Components' started by Lewin A.R.W. Edwards, Oct 31, 2004.

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  1. I'm trying to analyze a group of almost simultaneous failures in
    products that were released in 2002. The product is built on an x86
    motherboard, in a housing that meets or exceeds normal PC-case
    airflow. It SEEMS - and I'm still burning in a "repaired" board to
    test this theory - that the culprit parts are specific electrolytic
    caps used in various places over the PCB.

    The caps in question are G-LUXON 1000uF, 6.3V, 105 deg C rating, date
    code 0117(M). ALL of them are visibly bulged on top. Sticky dust-mud
    has gathered in the intersection of the score-marks on top, which
    leads me to believe that they bulged enough to break the can here and
    electrolyte has vented out. All the other electros on the board look
    normal. But then none of the other caps on the board are G-LUXON
    brand; they are mostly Sanyo.

    I'm wondering if this is a symptom of that problem people were talking
    about a while ago, where an incomplete/not-ready-for-primetime
    electrolyte formula was stolen and used in Chinese-made caps, which
    then exhibited an unusually high mortality rate.
     
  2. Dave Platt

    Dave Platt Guest

    Almost certainly. Luxon was reportedly one of the companies
    (Taiwanese) which purchased the bargain-priced (but defective)
    electrolyte from Luminous Electric in China.

    I had a pair of Apple Airport base stations go bad as the result of
    failed Luxon 'lytics. Neither had yet leaked, but both were bulging
    badly and had gone high-ESR. Replacement with another brand fixed the
    problem.

    You can probably expect most of the products built with the defective
    capacitors to fail, after a few hundred to a few thousand hours of
    operation, as the caps electrolyze away their electrolyte. As far as
    I know, replacement of the defective caps is the only preventive or
    curative measure.
     
  3. FWIW, Luxon (Taiwan based, but undoubtedly with China manufacturing)
    has denied involvment in that scandal.

    http://group.luxon.com.tw/



    Best regards,
    Spehro Pefhany
     
  4. Seems strange that they all went south, is it not also possible that the board
    had an on-board regulator failure??

    Just a thought.

    Peter
     
  5. RusH

    RusH Guest

    And Clinton didnt inhale. Pale of broken caps from Abit boards knows
    better.


    Pozdrawiam.
     
  6. The caps in question are G-LUXON 1000uF, 6.3V, 105 deg C rating, date
    It doesn't seem very likely. These caps smooth a 3.3V rail which runs
    all over the board. There is a group of four of these caps near the
    processor, and one near the RAM slots. Near a couple of other
    subassemblies, there are smaller (330uF 6.3V) caps on the same rail.
    These other caps are visually fine, and I pulled and tested a few at
    random and found them close to nominal value. It's just the G-LUXON
    1000uF caps that are bad. Most of them measure 5-10uF or open circuit.
     
  7. The caps in question are G-LUXON 1000uF, 6.3V, 105 deg C rating, date
    The runtime clocks on the failed units are, interestingly enough,
    clustered around an average of approx. 3,400 hours. Without looking
    through them all, I see the lowest at hand is 2171 and the highest is
    3709.

    Well, this is good and bad news, assuming that is in fact the only
    problem. It's good news in that the customer obstinately selected these
    particular boards instead of a more expensive board I had originally
    recommended ;). It's bad news in that I think I'll be asked to repair
    them all rather than testing and requalifying some new motherboard.

    One of those "quick" contracts that rears up a couple of years later to
    bite one's hindquarters. Oh well. Thanks for the reply. I hope the one I
    repaired is still running on Wednesday, because if so I think the
    problem's fixed (it usually shows up within an hour of powerup after
    cold, I figure a few days trouble-free is fairly safe).
     
  8. On Sun, 31 Oct 2004 18:50:57 +0000 (UTC), the renowned Peter A Forbes
    If one goes high ESR, it increases the power dissipation in the
    remaining good caps.


    Best regards,
    Spehro Pefhany
     
  9. It's because the defective electrolyte produced gas at a consistent
    rate.

    Of course, it's likely that a regulator failure would fry the board
    BECAUSE the capacitors failed.
     
  10. me

    me Guest

    They are usually used as the filters on a switching power supply.
     
  11. Uwe Bonnes

    Uwe Bonnes Guest

    : > >The caps in question are G-LUXON 1000uF, 6.3V, 105 deg C rating, date
    : > >code 0117(M). ALL of them are visibly bulged on top. Sticky dust-mud
    : >
    : > Seems strange that they all went south, is it not also possible that the board
    : > had an on-board regulator failure??

    : It doesn't seem very likely. These caps smooth a 3.3V rail which runs
    : all over the board. There is a group of four of these caps near the
    : processor, and one near the RAM slots. Near a couple of other
    : subassemblies, there are smaller (330uF 6.3V) caps on the same rail.
    : These other caps are visually fine, and I pulled and tested a few at
    : random and found them close to nominal value. It's just the G-LUXON
    : 1000uF caps that are bad. Most of them measure 5-10uF or open circuit.

    Are you sure you didn't touch the ripple current specs of the caps? I guess,
    near the processor and the switching regulator the caps will carry a
    substantial ripple current.
     
  12. Dave Hansen

    Dave Hansen Guest

    For your pleasure and enjoyment, an excerpt from an old comp.risks
    digest:

    --- Begin Included File ---
    ------------------------------

    Date: Tue, 20 May 2003 16:44:19 -0400
    From: "Jay R. Ashworth" <>
    Subject: The Great Capacitor Scare of 2003

    In RISKS-19.13, Mich Kabay quoted the *EE Times* on "The Great
    Capacitor Scare Of 1997". People were building motherboards without
    enough power supply filter caps, it seems, and machines were locking
    up.

    Oh, to have problems that minor again...

    The Great Capacitor Scare of 2003 is going to be *much* worse.

    It seems, according to several news stories (linked at the end) that a
    materials chemist who worked for a Japanese company, Rubycon
    Corporation -- which manufactured electrolyte for electrolytic (! :)
    capacitors -- left his employ, and ended up working for a Chinese
    capacitor maker, Luminous Town Electric. (These names tend to sound
    quaintly amusing to USAdian ears, which might not be accidental...)
    Apparently, in a fairly clear case of corporate espionage, the
    fellow's cow-orkers then "defected with the formula" (PCN says, in a
    confusing bit; defected to where he was?), and began to sell the
    electrolyte to many Taiwanese capacitor makers.

    Alas, there was one small problem.

    The formula wasn't *complete*. The capacitors, which ought to have
    been good (in some cases) for up to 4000 hours, were failing in half
    that -- or, if you believe Intel, in as little as 250 hours. The
    electrolyte apparently outgasses hydrogen, and pops the seals on the
    cap, leaking electrolyte onto the board. The missing ingredient was
    the one which prevented this. I'd speculate that this might not be a
    point-catastrophic failure... these caps might pop and leak out
    slowly, shorting out circuits.

    But it's even worse.

    The Inquirer may put it best:

    "It is not currently known how many market segments may have been
    affected by these poor parts, which can be found in motherboards,
    switchmode power supplies, modems and other PC boards. The
    failures of the aluminum capacitors might just be the 'tip of the
    iceberg,' says Zogbi. "Other component failures from low-cost Asian
    suppliers might be forthcoming," he warns.

    "Around 30 per cent of the world's supply of aluminum capacitors is
    manufactured in Taiwan, according to the Paumanok Group. Confusion
    over which manufacturers may have used the faulty electrolyte is
    sending buyers back to Japan to source their capacitors. The
    extent of the problem in product that has already shipped won't become
    clear until components start failing, which may not happen until
    halfway through the products' life expectancy. "

    But even *that* may understate the problem...

    How many electronic products do *you* know of that use electrolytic
    capacitors? The RISKS are so obvious that I don't even have to say
    "The RISKS are obvious". [But you did anyway! PGN]

    *The Inquirer* coverage is at http://www.theinquirer.net/?article=6085


    *Passive Component News* is at http://www.niccomp.com/taiwanlowesr.htm

    Check out the tenor of the editorial footnote; it's as classic as it
    is uncommon.

    TTI, who bill themselves as "The world's leading distributor of
    Passive, Interconnect, and Electromechanical components" have put up
    an entire page tracking press coverage of the issue:
    http://www.ttiinc.com/MarketEye/Aluminum_Cap_Issue.asp

    Jay R. Ashworth, The Suncoast Freenet, Tampa Bay, Florida
    http://baylink.pitas.com +1 727 647 1274

    --- End Included File ---

    I haven't checked to see if the referenced links are still up. FWIW,
    yours is the first problem regarding these electrolytics (if your
    problem _is_ these electrolytics) that I've heard about.

    Regards,

    -=Dave
     
  13. My thoughts also. If this is indeed a 3.3V line for a power-hungry processor
    the caps needs to be very low ESR types or many of them in parallel

    Cheers

    Klaus
     
  14. Usually *both*.


    Best regards,
    Spehro Pefhany
     
  15. : It doesn't seem very likely. These caps smooth a 3.3V rail which runs
    I didn't design the board - it's an off-the-shelf Pentium III
    motherboard. These systems are due for replacement in a little less
    than nine months. I figure the new caps ought to last this long, since
    they previously lasted more than two years.
     
  16. Ed Beroset

    Ed Beroset Guest

    I first read about the cap problem in IEEE Spectrum. The online version
    of the article is here
    http://www.spectrum.ieee.org/WEBONLY/resource/feb03/ncap.html

    That article specifically mentions Luxon caps, but also says that the
    company denies producing any faulty caps.

    Ed
     
  17. Ed Beroset

    Ed Beroset Guest

    In the name of completeness, at least two other explanations are possible:
    1. They really didn't produce any bad parts and the reports are wrong.
    2. They did produce bad parts but were/are not aware of it.

    However, personally, I find your expanations more plausible...

    Ed
     
  18. They could be lying or they could have been counterfeit components (a
    definite risk in China).



    Best regards,
    Spehro Pefhany
     
  19. Flawlessly logical, Mr. Spock, err, Ed.

    But I was taking into account the many reports on the web of Luxon
    branded parts failing (at least one of which is from someone I know
    not to be an agent of their competition. Also, I believe they actually
    denied using electrolyte made from the stolen formula. You may still
    be able to find the actual statement from the company (it used to
    exist on their web site) archived on the net (I did when I looked). If
    they actually denied producing any faulty parts at all, ever, you'd
    *know* they were lying. ;-)


    Best regards,
    Spehro Pefhany
     
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